Clear Channel Radio is going up against Pandora by celebrating the launch of the new iHeartRadio.  It will be kicked off with a two-day music festival hosted by Ryan Seacrest, host of American Idol, marking the beginning of the online free digital service and the biggest live concert festival in radio history.

The line-up for the festival is unbelievable, and there are a host of A-list performers ready to perform. The line-up includes: Lady Gaga, Coldplay, Alicia Keys, Steven Tyler, The Black Eyed Peas, Kenny Chesney, Jennifer Lopez, Carrie Underwood, Jane’s Addiction, Nicki Minaj, John Mayer, David Guetta, Rascal Flatts, Bruno Mars, Kelly Clarkson, Sublime with Rome and special performances from Usher and Sting, with more to be announced.

New iHeartRadio will combine more than 750 broadcast radio and digital-only stations from 150 cities with the ability to create custom stations, delivering listeners everything they want all in one fully integrated service.

“Music is the heart of our business and we think there is no better way to celebrate the launch of the New iHeartRadio than with a groundbreaking, multi-day festival featuring the world’s biggest, most exciting artists – and reaching the largest combined U.S. radio and online audience ever,” said Bob Pittman, Chairman of Media and Entertainment Platforms for Clear Channel Radio. “The New iHeartRadio will offer users a much broader, more integrated and customized digital listening experience than any other service available – and it’s all in one product.”

It’s obvious that New iHeartRadio will compete against Pandora, the online radio platform that recently filed its IPO. I am looking forward to comparing numbers of unique users for each platform after the promotional music festival.

The live audio and video streams of the iHeartRadio Music Festival will be available online, via mobile devices and across all of Clear Channel’s radio station websites. “This is a once in a generation gathering of artists and fans from all over the country for a true, must-see music event,” said Ryan Seacrest, “The iHeartRadio Music Festival, like the iHeartRadio digital radio service, will showcase top artists across all genres of music. Listeners from all over America will travel to Las Vegas to celebrate the next generation of iHeartRadio, while seeing the greatest musicians in the world on one stage.”

With more than 45 million listening hours a month from its 27 million unique website visitors and 30 million downloads of the iHeartRadio mobile application. The challenger for Pandora currently offers more than 750 of America’s favorite radio stations from 150 cities and commercial-free, digital-only music, talk and comedy stations.

The promotional campaign for the festival and online radio platform has started already with movie and musical pop star Jennifer Lopez interview on the Today Show this morning.

The new online radio platform will deliver to users the broadcast radio stations as well as the ability to create custom stations with even more songs with no commercials through the end of the year, offering listeners everything they want digitally in one fully integrated service – free.